Process for treating coffee.



\,' UNITED STATES ATENT OFFICE.

PROCESS FOR TREATING- COFFEE.

!To Drawing.

To all whom it may concern.

Be it known that I, FRANCIS citizen of the UnitedStates, residing in the Specification of Letters Patent.

R. EDEN, a

town of Montclair, county of Essex, and.

State of New Jersey, have inventedcertain new and useful Improvements in Processes for Treating Cofi'ee, of which the following is a specification.

My invention relates to an improved process for the treatment of greencofiee beans whereby the cafi'ein is extracted therefrom and theremaining constituents of the bean are left unimpaired therein.

The objects of my invention are the production of a roasted coffee bean from whlch the cafl'ein-has been removed without the removal of the aromatic essentials therefrom, the preservation of the essential oil and the formation of empyreumatic oil in increased quantity, and to attain these results without the use of chemicals.

My process is a physical one, involving the expansion of the organic structure of the bean by moisture and heat, including the absorption of the moisture by the structural cells, and particularly by the innermost layer thereof, in which the cafi'ein of the .bean is localized; the extraction of the moisture, aided by the contraction ofthe bean in forcing it out, together with the liberated cafi'ein in solution therewith resulting from the partial decomposition of these cells; and the further extraction of the remaining cafl'ein by repetition .of. the foregoing step supplemented by mechanical withdrawal of the moisture effected by a centrifugal machine, and the immediate application to the bean of roasting heat at a temperature in excess of the normal roasting temperature for the same grade of untreated bean, whereby there is induced in the still moist interior of the bean the sublimation of the remaining caifein and the formation of steam or vapor, which, acting throughout the cellular structure of thebean, drives the essential oil to the surface; the-formation of empyreumatlc oil upon thesur'face, and the abrupt withdrawal of heat before volatilization of the aromatic oils has materially progressed.

As coffee beans readily imbibe exhalations from other bodies and thereby acquire adventitious and disagreeable flavors, the use :of chemical solvents of caife'in renders the production of a decafi'einated colfeebean whose natural flavor is unimpaired a prac FRANCIS B. EDEN, OF MONTCLAIR, NEW JERSEY.

Patented Feb. 20, 1917.

Application filed October 30, 1915. Serial N 0. 58,796.

tical impossibility; norcan the essential oil or other aromatic substances of the bean be restored thereto without impairment. 'In consequence of theseobjections it is found that'high grade cofl'ees chemically treated do not retain the same aroma or flavor and become less valuable after decafleinatio'n, 7 but by my improved process a low grade of coffee, after decafl'eination, is rendered more valuable, its aromatic properties and its flavor being retained and developed thereby.

The best method now known to me andthe manner in which such method is applied to attain the objects of my invention, are as follows Green coflee beans are immersed in water at a temperature of from 200 Fahrenheit to 212, the temperature varying with, and also the period of immersion depending upon, the grade of the coffee to be treated as well as the condition of the bean, its age, hardness, and the caffein-content, which may be between .6 and 2.2%. The beans remain immersed for a' period varying, for the reasons above given, from fifteen to twenty minutes, during which time sorbing water into their interior cells until they are saturated. This condition will be indicated by an increase in their volume of approximately 50%, and an increase in weight of from 20 to 25%.

The beans are then removed from the water and allowed to steam,.drain and con tract .for a period of about five minutes, when 'the operation of immersion is repeated. a 1

These immersions in water of the temperature named result in a forced tendency to germmation, whlch 1n many instances will be evidenced by the actual rupture of the outer wall of the bean. This tendency to. limited germination induces the liberation of the cafl'ein contained in the interior cellular layer of the bean from which the "sprout forms, and as cafl'ein is soluble in hot .water it is given up by the bean and passes off with the water ofsolution to such an extent that by the repetition of the immersion proximately of its contained cafl'ein.

The contraction of the bean by, the cooling resultant from its withdrawal from the hot baths materially assists in the exuding of the .oaffein. I s

It is to understood that these immer bean loses apof moisture as ofan increased percentage of .enough to extract example,

:been driven-ofi. This sults from the sion steps are only maintained long enough to soften and expand the beans, and not long any of the fatty substances or aromatic oils, which, being slower of solution, and non-water-soluble, are retained by the bean. Y

The coffee beans are. next transferred while moist and steaming to the cylinder of a centrifugal extractor, where substantially all of the water remaining is removed and with it in sol tion nearly all of the last traces of cafi'ein.

The fourth step in my process is the transfer of the beans from the centrifugal direct to a coffee roaster and their immediate roasting while still retaining interiorly such traces have not been drawn off by the extractor. the beans in this condition is an essentlal step in my process, and this roasting must be done quickly, and with a higher heat than is ordinarily used for untreated beans; for

untreated coffee, which requires for from 35 to 40 minutes, must rethe roaster for from 40 to 45 minthe preceding steps a heat higher than roasting main in uteswhen treated by of my process and with would otherwisebe used. While untreated r cofi'ee loses from 14 to 16%- in roasting, the coffee treated byQthe preceding steps of my process will amount. This is due to the fact that its weight is increased by the moisture absorbed and not driven off by the centrifugal; so that although its actual loss by the roasting step is from 20 to 24%, due to the driving off of the moisture, the net loss is substantially that of untreated cofiee. While my treated coffee is in the roaster for a longer time than is usual for untreated cofiee, the actual roasting takes place more quickly, as it does not begin until all the moisture has driving ofi of the moisture bythe roasterI regard as an important feature of my improved process,

since it involves driving to the surface, throughthe wall of the bean, all of the essential oils and fatty substances which are so valuable to the flavor-of the cofleef This expulsion of these matters to the surface reof the bean, and facilitates the formation The immediate roasting of lose substantially an equab impregnating moisture retained in the cells tial oil is driven empyreumatic' equal to New York Cofiee Exchange Type;

260 iarly hard and therefore very undesirable #4, crop 1915, known in the trade as peculas to cup quality. This coffee was soaked for 20 minutes at a temperature of 212 and drained for five minutes, again soaked at the same temperature for the same period, centrifuged for five minutes, and then roasted for 40 minutes.

The beverage made from this cofi'ee loses the hard and bitter flavor characteristic of this quality of coffee and becomes so modified as to be equal in flavor and aroma to the most desirable quality coffee of this type.

Having thus described my invention and the best method now known to me of practising the same, I claim:

1. The described process for treatment of green cofiee beans consisting in extracting the caifein therefrom by immersion in water at a temperature at which caffein is readily soluble, driving oif the water from the beans, and roasting them while moist.

2. The step in the described process consisting in roasting decafieinated coffee beans while moist.

3. The described process for treatment of green cofiee beans consisting in, roasting the beans from which the cafi'ein has been withdrawn by the extractive action of water While moist.

4. The process f treatment of green coffee beans consisting in moistening said "beans and roasting While moist.

5. The method of increasing the empyreumatic oil of coffee beans consisting in the cells of the green bean vaporizing said moisture, and

with moisture,

the essential oil 1s driven roasting whereby out by theexpanding vapor.

6.'The methodof increasing the empyreumatic oil of roasted cofi'ee consisting in impregnating'the cells of thegreen bean with moisture, vaporizing said moisture, and roasting during the period that essento the surface but without volatilization thereof.

FRANCIS K; EDEN. 

